1. Field of the Invention
This invention relates to the carburetor art and more particularly to a carburetor for a liquified petroleum gas, such as propane, powered internal combustion engine for providing a multi-stage pressure reduction of the gas phase of the liquified petroleum gas contained in a liquified petroleum gas storage bottle which contains both the liquid phase and the gas phase of the liquified petroleum gas and metering the amount of the gas for mixing of the gas with ambient air before introduction of the gas/air mixture into the internal combustion engine.
2. Description of the Prior Art
Carburetors of various configurations have heretofore been utilized in connection with providing metered amounts of fuel with air, at either ambient pressure or supercharged, to provide a fuel/air mixture before introducing the fuel/air mixture into, for example, the intake manifold of an internal combustion engine for distribution of the fuel/air mixture to the cylinders of the internal combustion engine. While the advent of direct fuel injection of the fuel into the cylinders of the internal combustion engine has decreased the use of carburetors for many liquid fuel, such as gasoline, powered devices, there are still many applications wherein a carburetor may be economically advantageous utilized.
In gasoline powered internal combustion engines, utilizing a carburetor to mix the gasoline with the air, in general the liquid gasoline is mixed with the air in the carburetor and the liquid gasoline/air mixture flows from the carburetor into an intake manifold of the internal combustion engine. From the intake manifold the liquid gasoline/air mixture is introduced into the individual cylinders of the internal combustion engine. In each cylinder, some or all (depending on the type of engine) of the liquid gasoline is converted into the vapor stage where a spark plug ignites the mixture to provide the power stroke of the piston in the cylinder. The carburetor is generally connected in gas flow communication to the intake manifold so as to be substantially heat isolated from the intake manifold and the internal combustion engine since heating the carburetor might cause the gasoline to convert into the vapor phase in the carburetor which would “vapor lock” the carburetor and prevent the introduction of the desired metered amount of flow of liquid gasoline for mixing with the ambient air.
One present use of carburetors, however, is in the field of gas phase powered internal combustion engines wherein the fuel is the gas phase of a liquified petroleum gas. The containers of the liquified petroleum gas contain both liquid phase and gas phase of the liquified petroleum gas which, for example may be propane. The pressure of the gas phase of the liquified petroleum gas in the container may be on the order of 150 pounds per square inch and, as such, the pressure must be reduced before the metered amount of gas may be mixed with the air to provide the desired mixture of gas/air for introduction into the cylinders of the internal combustion engine. In the prior art a separate pressure regulator has generally been utilized to provide the desired reduction in the gas pressure. However, a separate pressure regulator has often introduced complications in the design of the fuel system for such gas powered internal combustion engines. One such complication is the instance of the liquid being introduced into the regulator. In such instances, generally the liquid phase will convert into the gas phase. In so converting to the gas phase, the regulator will be cooled as the liquid absorbs heat from the structure of the regulator and the performance of the regulator will be erratic. Should such introduction of liquid of the liquid phase into the carburetor continue long enough, there will be no conversion of the liquid phase to the gas phase and the liquid phase of the liquified petroleum gas will remain in the regulator. Since the internal combustion engine is designed to operate on the gas phase, and not the liquid phase, as the fuel in the fuel/air mixture, the engine would cease functioning until the gas phase in the correct metered amount is mixed with the air.
Thus, there has long been a need for a fuel system for gas powered internal combustion engines wherein both the pressure regulation of the gas, the metering of the gas flow and the combining of the metered gas flow with the air is accomplished in a single unit before introduction of the gas/air mixture into the intake manifold of the engine. Further, in providing such a combination pressure regulator and metering of the gas phase into the air flow in the desired ratio, such single should insure that only gas phase of the fuel is introduced with the ambient air to provide the desired gas/air mixture even though some liquid phase may enter the unit. That is, even if liquid phase enters the unit, the unit must provide that only gas phase is ultimately mixed with the ambient air to provide the desired gas/air mixture for the engine and liquid phase does not enter the engine.
Accordingly, there has long been a need for a carburetor for use in a gas powered internal combustion engine that incorporates both the pressure regulation of the gas as well as the metering of the pressure regulated gas into the air flow to provide the desired gas/air ratio mixture for introduction into the intake manifold of the internal combustion engine.
Accordingly, it is an object of the present invention to provide a combination pressure regulator and carburetor for use in a gas powered internal combustion engine.
It is another object of the present invention to provide a combination pressure regulator and carburetor for use in a gas powered internal combustion engine that minimizes or eliminates any flow of liquid phase of the fuel into the intake manifold of the engine.
It is yet another object of the present invention provide a combination pressure regulator and carburetor for use in a gas powered internal combustion engine wherein the carburetor is positioned in relationship to the internal combustion engine to receive heat therefrom so as to convert any liquid introduced therein into the gas phase.
It is still another object of the present invention to provide a combination pressure regulator and carburetor for use in a gas powered internal combustion engine in which the gas phase of the liquified petroleum gas is metered into the air flow in the desired amount to provide a gas/air mixture corresponding to the operating condition of the internal combustion engine.
It is still another object of the present invention provide a combination pressure regulator and carburetor for use in a gas powered internal combustion engine which may be mounted on the intake manifold or in close proximity thereto so as to absorb heat therefrom.